Background Heparin dosage for anticoagulation during
cardiopulmonary bypass (CPB) is commonly calculated based on the patient's
body weight. The
protamine-
heparin ratio used for
heparin reversal varies widely among institutions (0.7-1.3 mg
protamine/100 IU
heparin). Excess
protamine may impair coagulation. With an empirically developed algorithm, the HeProCalc program,
heparin, and
protamine doses are calculated during the procedure. The primary aim was to investigate whether HeProCalc-based dosage of
heparin could reduce
protamine use compared with traditional dosages. The secondary aim was to investigate whether HeProCalc-based dosage of
protamine affected postoperative
bleeding. Patients and Methods We consecutively randomized 40 patients into two groups. In the control group, traditional
heparin and
protamine doses, based on
body weight alone, were given. In the treatment group, the HeProCalc program was used, which calculated the initial
heparin bolus dose from weight, height, and baseline activated clotting time and the
protamine dose at termination of CPB. Results We analyzed the results from 37 patients, after exclusion of three patients. Equal doses of
heparin were given in both groups, whereas significantly lower mean doses of
protamine were given in the treatment group versus control group (211 ± 56 vs. 330 ± 61 mg, p < 0.001). Postoperative
bleeding was less in the HeProCalc group (280 ± 229 mL) as compared with the control group (649 ± 279 mL). However, this difference was not found statistically significant (p = 0.074). Conclusion HeProCalc-based dosage of
heparin and
protamine allowed for reduced
protamine use after CPB compared with when conventional calculations were used. Furthermore, HeProCalc-based regimen for
heparin reversal suggested less postoperative
bleeding, although the difference between the groups was not statistically significant.